On Sat, Jul 29, 2023 at 04:37:00PM +0800, Zhangjin Wu wrote:
> > This one does not have the correct prototype for the function exposed
> > to the user, pipe really is "int pipe(int pipefd[2])". Maybe you were
> > thinking about sys_pipe() instead ? But since MIPS also has pipe2() now,
> > there's no reason to make an exception.
> >
>
> Yes, pipe2() should be a better choice, but I have seen this sentence in
> syscall manpage [1]:
>
> /* On Alpha, IA-64, MIPS, SuperH, and SPARC/SPARC64, pipe() has the
> following prototype; see NOTES */
>
> #include <unistd.h>
>
> struct fd_pair {
> long fd[2];
> };
> struct fd_pair pipe(void);
>
> If it is about syscall, then we are ok to align all of the architectures
> together to use "int pipe(int pipefd[2])"
Yes it's OK, that's how applications expect it to be used:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pipe.html
For the archs you mention above, it's the libc that wraps the call,
exactly what we ought to do as well (using pipe2() since it will be
easier).
Willy
